Plate tumbler plugs



I R. C. SPAIN PLATE TUMBLER PLUGS Nov. 14, 1967 Original Filed Aug. 24, 1965 2 Sheets-Sheet 1 Nov. 14, 1967 R. c. SPAIN PLATE TUMBLER PLUGS 2 Sheets-Sheet 2 Original Filed Aug. 24, 196

United States Patent Ofiice 3,352,135 Patented Nov. 14, 1967 4 Claims. c1. 70-375 ABSTRACT OF THE DISCLOSURE A plate tumbler plug for a lock cylinder formed in one piece in a single die casting operation and having a generally cylindrical body with an enlarged end and an opposite reduced end. The plug has a central keyway extending therethrough and terminating within the reduced end, and a plurality of axially spaced slots extending diametrically therethrough and intersecting the keyway; the slots being provided with enlargements formed at one side for springs for the tumblers. The plug is formed with a side core that forms the key guides, the key support and a lateral opening, and a pair of opposed cores for the plurality of slots.

The present application is a division of applicants copending application Ser. No. 482,248, filed Aug. 24, 1965, and entitled Method and Apparatus for Die Casting Key Plugs.

The present invention relates to a plate tumbler plug and more particularly to a novel die cast plate tumbler plug which is stronger and has more dimensional control than presently produced plate tumbler plugs.

Among the objects of the present invention is the provision of a novel plate tumber plug which is more consistent and dimensionally stable than previously produced plugs formed from two separate pieces in a plug die. There is better dimensional control of the key support and the key guides in the plug due torthe improved fabrication of the plug. The centrally located key support is directly under the tumblers and is made by the use of a single block or side core, and the key guides are formed by the same solid side core that forms the key support.

Another object of the present invention is the provision of a die cast plate tumbler plug where the holes or channels for the tumbler springs are all located on the same side of the center line of the plug. This permits the formation of a stronger plug by forming two solid and uninterrupted columns that run the entire length of the plug.

A further object of the present invention is the provision of a die cast plate tumbler lock plug wherein it is easier and less costly to change the keyway in the plug. This alteration occurs through a change only in a solid die core utilized in the die casting mold for forming the plug.

Further objects are to provide a construction of maximum simplicity, efiiciency, economy and ease of fabrication, and such further objects, advantages and capabilities as will later more fully appear and are inherently possessed thereby.

In the drawing:

FIGURE 1 is an enlarged side elevational view of the plate tumbler key plug.

FIG. 2 is a front elevational view of the key plug of FIG. 3..

FIG. 3 is another side elevational view of the key plug taken from a position 90 removed from the view of FIG. 1.

FIG. 4 is a cross sectional view of the key plug taken on the line 44 of FIG. 2.

FIG. 5 is another cross sectional view taken on the line 5-5 of FIG. 3.

FIG. 6 is an enlarged cross sectional view taken on the line 6-6 of FIG. 1.

FIG. 7 is a cross sectional view taken on the line 7-7 of FIG. 3.

FIG. 8 is a rear elevational view of the key plug.

FIG. 9 is a partial side elevational view enlarged from the dotted circle shown in FIG. 3. 7

Referring more particularly to the disclosure in the drawing wherein is shown an illustrative embodiment of the present invention, FIG. 1 discloses a key plug 10 which is adapted for use with plate-type tumblers, and includes a cylindrical body 11 with a reduced rear end 12 and an enlarged head or flange 13 at its forward end. A radially extending arcuate projection or lug 14 is formed on the underside of the flange 13- and interengages or cooperates with an encompassing cylinder for the plug for locating and limiting rotation of the plug therein. The reduced end 12 is provided with a recess 15 for attachment to a bolt or other locking arrangement.

The plug 10 is provided with a keyway 16 extending through the flange 13 and body 11 and into and terminating in the reduced end 12 (FIGS. 4 and 5) and having a concavity providing camming entrance surfaces 17 at the face of the plug; the keyway 16 being provided with three key wards 18 formed in the head of the plug only. These wards run into the grooves formed in the sides of the key, which is called a paracentric key (not shown). The plug 10 is also provided with key guides 19 which also run in the grooves in the key; the guides being in alignment with one of the key wards 18 (see FIG. 4). The guides 19 prevent an improperly bitted key from being lifted and used to pick the lock when the improper key is inserted therein. These key guides are cast into and located in the same block or side core of steel which make the key supported surfaces resulting in a most precise location of the guides.

The plug is also provided with centrally located spaced and aligned key supports 21 which are located directly under the tumblers in the assembly lock and formed by the utilization of a unitary solid core that forms the opening 22 in the side of the plug 10 during the die casting operation and also forms the key guides 19. The surface 23 in the front or head of the plug 10 is lower than the key support 21 and does not support the key, and also the surface 24 in the back or rear of the plug which formerly supported the key is lower than the support 21 and also does not provide support for a key.

The plug is further provided with a plurality of spaced slots 25 which open at diametrically opposite sides of the plug and intersect the opening 22 within the plug. The slots are provided to receive plate-type tumblers to be inserted in the plug -10 when the plug is assembled in a cylinder. The slots 25 at one side are enlarged to provide openings or channels 26 adapted to receive the tumbler springs. These latter openings are all located on the same side of the center line for the plug permitting a stronger plug to be made by forming two solid and uninterrupted columns 27 (see FIG. 7) that run the length of the plug. As seen in FIG. 7, the slots 25 are all formed with shoulders 28 terminating the extent of the openings 26 to provide an abutting surface for one end of a spring; the opposite end of the spring abutting a projection or other reaction surface on the plate-type tumbler in the plug.

Although one embodiment of the present plate tumbler plug has been shown and described, it is not my desire or intent to unnecessarily limit the scope or utility of the novel features by virtue of this illustrative embodiment.

Having thus disclosed my invention, I claim:

1. A plate-type tumbler plug for a cylinder lock assembly formed as an integral unit assembly in a die casting operation, comprising a generally cylindrical integral key plug having an enlarged flange forming a head at a front end of the plug and a reduced opposite rear end, said plug having a central keyway extending axially into the plug from the flange end and extending through the plug and into and terminating within said reduced end, a plurality of slots extending diametrically through said plug and intersecting said keyway, an enlargement in each of said slots extending partially through the plug and terminating in a shoulder, said enlargements all being positioned at one side of said keyway, centrally located and aligned key supports formed in said keyway, a plurality of longitudinally aligned key guides formed in and projecting into the keyway and spaced from said key supports, said key supports and key guides being formed by a single side core extending into the plug during casting, said core also forming a lateral opening intersecting said keyway, an axially extending surface defining the keyway in the front end of the plug, and an axially extending surface in the rear end of said plug aligned With said first mentioned surface, said axially extending surfaces extend less than said key supports wherein said axially extending surfaces are out of alignment with said key supports so that a proper key, when inserted in the plug, rests only on said key supports intermediate said axially extending surfaces.

2. A plate-type tumbler plug as set forth in claim 1, including key wards formed solely in the front end of said plug, one of said key wards being aligned with said key guides.

3. A plate-type tumbler plug as set forth in claim 1, in which said enlargements are aligned parallel to the longitudinal axis of the plug and the positioning of the enlargements permits a stronger plug having tWo solid and uninterrupted parallel columns extending the entire length of the plug.

4. A plate-type tumbler plug as set forth in claim 1, including a radially projecting lug formed on the underside of the enlarged flange at the front end of the plug.

References Cited UNITED STATES PATENTS 1,664,404 4/1928 Douglas 70--364 1,789,755 1/1931 Jacobi 70375 3,002,268 10/1961 Spain 70372 X 3,170,317 2/1965 Parlier 70364 3,186,199 6/1965 Schwartz 70364 X MARVIN A. CHAMPION, Primary Examiner.

EDWARD C. ALLEN, Examiner.

P. TEITELBAUM, Assistant Examiner. 

1. A PLATE-TYPE TUMBLER PLUG FOR A CYLINDER LOCK ASSEMBLY FORMED AS AN INTEGRAL UNIT ASSEMBLY IN A DIE CASTING OPERATION, COMPRISING A GENERALLY CYLINDRICAL INTEGRAL KEY PLUG HAVING AN ENLARGED FLANGE FORMING A HEAD AT A FRONT END OF THE PLUG AND A REDUCED OPPOSITE REAR END, SAID PLUG HAVING A CENTRAL KEYWAY EXTENDING AXIALLY INTO THE PLUG FROM THE FLANGE END AND EXTENDING THROUGH THE PLUG AND INTO AND TERMINATING WITHIN SAID REDUCED END, A PLURALITY OF SLOTS EXTENDING DIAMETRICALLY THROUGH SAID PLUG AND INTERSECTING SAID KEYWAY, AN ENLARGEMENT IN EACH OF SAID SLOTS EXTENDING PARTIALLY THROUGH THE PLUG AND TERMINATING IN A SHOULDER, SAID ENLARGEMENTS ALL BEING POSITIONED AT ONE SIDE OF SAID KEYWAY, CENTRALLY LOCATED AND ALIGNED KEY SUPPORTS FORMED IN SAID KEYWAY, A PLURALITY OF LONGITUDINALLY ALIGNED KEY GUIDES FORMED IN AND PROJECTING INTO THE KEYWAY AND SPACED FROM SAID KEY SUPPORTED, SAID KEY SUPPORTS AND KEY GUIDES BEING FORMED BY A SINGLE SAID CORE EXTENDING INTO THE PLUG DURING CASTING, SAID CORE ALSO FORMING A LATERAL OPENING INTERSECTING SAID KEYWAY, AN AXIALLY EXTENDING SURFACE DEFINING THE KEYWAY IN THE FRONT END OF THE PLUG, AND AN AXIALLY EXTENDING SURFACE IN THE REAR END OF SAID PLUG ALIGNED WITH SAID FIRST MENTIONED SURFACE, SAID AXIALLY EXTENDING SURFACES EXTEND LESS THAN SAID KEY SUPPORTS WHEREIN SAID AXIALLY EXTENDING SURFACES ARE OUT OF ALIGNMENT WITH SAID KEY SUPPORTS SO THAT A PROPER KEY, WHEN INSERTED IN THE PLUG, RESTS ONLY ON SAID KEY SUPPORTS INTERMEDIATE SAID AXIALLY EXTENDING SURFACES. 